Galaxy Morphology in the Rich Cluster Abell 2390

Abstract

We have analysed images of the field of A2390 obtained with the CFHT and HST. The analysis fits models to bulge and disk components to several hundred galaxies, with about equal samples from the cluster and field. We also have assessed and graded asymmetries in the images. The cluster galaxies are compared in different cluster locations and also compared with field galaxies. We find that the central old population galaxies are bulge-dominated, while disk systems have young populations and are found predominantly in the outer cluster. S0 and bulgy disk galaxies are found throughout, but concentrate in regions of substructure. Disks of cluster blue galaxies are generally brighter and smaller than those in the field. We find that the cluster members have a higher proportion of interacting galaxies than the field sample. Interactions in the cluster and in the field, as well as cluster infall, appear to inhibit star-formation in galaxies.1 Number of galaxies with morphology measurements 2 Proportional to the product of telescope throughput, exposure, and pixel area on sky.

Surveys of High-Redshift QSO Hosts

“…Thus, necessarily shallow HST imaging data will not detect or measure structures beyond the spheroidal population (see Fig 3). We also find (Hutchings et al 2001) from comparing intermediate-redshift galaxy clusters and field galaxies, that galaxies in an interaction-rich environment have brighter bulges and fainter disks as a result.…”

Cl 1358+62: Characterizing the Physical Properties of Cluster Galaxies atz= 0.33

“…By comparing spectral features to quantitative measures of galaxy morphology from our extensive sample of CL 1358+62 (z = 0.3283; Fisher et al 1998, hereafter F98), we can address this issue as well as test for correlations between morphology and cluster substructure (e.g. Hutchings et al 2002).…”